@scaccogatto,

You can try like as below to see if it can work:

on:
  push:
    tags:
      - 'v*'

OR

on:
  push:
    tags:
      - 'v**'

In addition, how did you push these tags to the repository? Manually executed the related git commands on your local machine to push tags, or executed the related git commands in a workflow to push tags?

If you used a workflow, what token did you use to authenticate? A personal access token (PAT) or the GITHUB_TOKEN?

If you used the GITHUB_TOKEN to push tags, it is the correct behavior that the workflow was not triggered. Because (see here):

When you use the repository’s GITHUB_TOKEN to perform tasks on behalf of the GitHub Actions app, events triggered by the GITHUB_TOKEN will not create a new workflow run. This prevents you from accidentally creating recursive workflow runs.

I am pushing with git push --follow-tags.
@Simran-B solved it! Thanks!